View Full Version : Turboprop

25th Mar 2002, 22:53
Just a silly question-. .. .Why does torque increase as you gain speed on a turboprop engine...?. .. .Best regards

25th Mar 2002, 23:35
Ram air effect?

26th Mar 2002, 15:10
To be specific,. .. .the amount of air that "passes trough the prop", increases with airspeed. You would expect that the prop would start to spin faster, but it doesn't because you have set a constant rpm with your conditon levers. So instead the torque increases as power is a function of airspeed. <img border="0" title="" alt="[Smile]" src="smile.gif" />

26th Mar 2002, 16:50
N4641P . .. .Thanks for the help........I appreaciate it.. .Regards

26th Mar 2002, 23:30
As your speed increases you need more thrust, i.e. torque.

27th Mar 2002, 19:45
Tinstaafl provided the correct answer.. .. .Power is a function of torque and RPM. Propeller torque is a function of propeller pitch, RPM and airspeed. The interesting thing here, power turbine torque, is a function of RPM and engine air mass flow. RPM will be held constant by the prop governor but the ram air effect will increase the air flow for a given power setting. Alas, you end up with torque blooming as you pick up speed.. .. .Cheers,. . Fred